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octomap_mapping: octomap | octomap_server

Package Summary

octomap_server loads a 3D map (as Octree-based OctoMap) and distributes it to other nodes in a compact binary format. See octomap_saver on how to request or save a map file. A visualization of the occupied cells is sent as MarkerArray.

• Author: Armin Hornung
• License: BSD
• Repository: alufr-ros-pkg
• Source: svn http://alufr-ros-pkg.googlecode.com/svn/trunk/octomap_stacks/octomap_mapping/octomap_server

ROS Node API

octomap_server

octomap_server builds and distributes volumetric 3D occupancy maps as OctoMap binary stream and in various ROS-compatible formats e.g. for obstacle avoidance or visualization. The map can be a static OctoMap .bt file (as command line argument) or can be incrementally built from incoming range data (as PointCloud2). octomap_server starts with an empty map if no command line argument is given. In general, octomap_server creates and publishes only on topics that are subscribed. Since some can be time-consuming to build for large maps, only subscribe to topics you absolutely need (e.g. in RViz) and set the "latch" parameter for false when building maps.

Subscribed Topics

cloud_in (sensor_msgs/PointCloud2)

• Incoming 3D point cloud for scan integration. You need to remap this topic to your sensor data and provide a tf transform between the sensor data and the static map frame.

Published Topics

octomap_binary (octomap_ros/OctomapBinary)

• The complete maximum-likelihood occupancy map as compact OctoMap binary stream, encoding free and occupied space.

occupied_cells_vis_array (visualization_msgs/MarkerArray)

• All occupied voxels as "box" markers for visualization in RViz. Be sure to subscribe to the topic occupied_cells_vis in RViz!

octomap_point_cloud_centers (sensor_msgs/PointCloud2)

• The centers of all occupied voxels as point cloud, useful for visualization. Note that this will have gaps as the points have no volumetric size and OctoMap voxels can have different resolutions! Use the MarkerArray topic instead.

octomap_collision_object (arm_navigation_msgs/CollisionObject)

• All occupied voxels as "box" CollisionObjects, e.g. for collision avoidance in arm_navigation

map (nav_msgs/OccupancyGrid)

• Downprojected 2D occupancy map from the 3D map. Be sure to remap this topic if you have another 2D map server running

Services

octomap_binary (octomap_ros/GetOctomap)

• The complete maximum-likelihood occupancy map as compact OctoMap binary stream, encoding free and occupied space.

~clear_bbx (octomap_ros/ClearBBXRegion)

• Clears a region in the 3D occupancy map, setting all voxels in the region to "free"

~reset (std_srvs/Empty)

• Resets the complete map

Parameters

~frame_id (string, default: /map)

• Static global frame in which the map will be published. A transform from sensor data to this frame needs to be available when dynamically building maps.

~resolution (float, default: 0.05)

• Resolution in meter for the map when starting with an empty map. Otherwise the loaded file's resolution is used.

~base_frame_id (string, default: base_footprint)

• The robot's base frame in which ground plane detection is performed (if enabled)

~height_map (bool, default: false)

• Whether visualization should encode height with different colors

~sensor_model/max_range (float, default: -1 (unlimited))

• Maximum range in meter for inserting point cloud data when dynamically building a map. Limiting the range to something useful (e.g. 5m) prevents spurious erroneous points far away from the robot.

~sensor_model/[hit|miss] (float, default: 0.7 / 0.4)

• Probabilities for hits and misses in the sensor model when dynamically building a map

~sensor_model/[min|max] (float, default: 0.12 / 0.97)

• Minimum and maximum probability for clamping when dynamically building a map

~latch (bool, default: True for a static map, false if no initial map is given)

• Whether topics are published latched or only once per change. For maximum performance when building a map (with frequent updates), set to false. When set to true, on every map change all topics and visualizations will be created.

~filter_ground (bool, default: false)

• Whether the ground plane should be detected and ignored from scan data when dynamically building a map, using pcl::SACMODEL_PERPENDICULAR_PLANE. This clears everything up to the ground, but will not insert the ground as obstacle in the map. If this is enabled, it can be further configured with the ~ground_filter/... parameters.

~ground_filter/distance (float, default: 0.04)

• Distance threshold for points (in z direction) to be segmented to the ground plane

~ground_filter/angle (float, default: 0.15)

• Angular threshold of the detected plane from the horizontal plane to be detected as ground

~ground_filter/plane_distance (float, default: 0.07)

• Distance threshold from z=0 for a plane to be detected as ground (4th coefficient of the plane equation from PCL)

~pointcloud_[min|max]_z (float, default: -/+ infinity)

• Minimum and maximum height of points to consider for insertion in the callback. Any point outside of this intervall will be discarded before running any insertion or ground plane filtering. You can do a rough filtering based on height with this, but if you enable the ground_filter this interval needs to include the ground plane.

~occupancy_[min|max]_z (float, default: -/+ infinity)

• Minimum and maximum height of occupied cells to be consider in the final map. This ignores all occupied voxels outside of the interval when sending out visualizations and collision maps, but will not affect the actual octomap representation.

Required tf Transforms

sensor data frame → /map (static world frame, changeable with parameter frame_id)

• Required transform of sensor data into the global map frame if you do scan integration

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